Dietes Species, Butterfly Iris, Fairy Iris, Fortnight Lily, Large Wild Iris

Dietes grandiflora

Family: Iridaceae (eye-rid-AY-see-ee) (Info)
Genus: Dietes (dy-AY-teez) (Info)
Species: grandiflora (gran-dih-FLOR-uh) (Info)



Water Requirements:

Drought-tolerant; suitable for xeriscaping

Sun Exposure:

Sun to Partial Shade



Foliage Color:

Unknown - Tell us


36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 m)


18-24 in. (45-60 cm)


USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Where to Grow:

Grow outdoors year-round in hardiness zone

Can be grown as an annual


Unknown - Tell us

Bloom Color:

Pale Yellow

White/Near White

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Bloom Size:

Unknown - Tell us

Bloom Time:

Mid Spring

Late Spring/Early Summer

Other details:

Unknown - Tell us

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:


Propagation Methods:

By dividing rhizomes, tubers, corms or bulbs (including offsets)

From seed; direct sow after last frost

Seed Collecting:

Allow seedheads to dry on plants; remove and collect seeds

Properly cleaned, seed can be successfully stored


This plant is said to grow outdoors in the following regions:

Glendale, Arizona

Long Beach, California

Moreno Valley, California

Oceanside, California

Salinas, California

San Francisco, California

San Jose, California

San Leandro, California

Stockton, California

Bokeelia, Florida

Jacksonville, Florida

Lecanto, Florida

Orlando, Florida

Tampa, Florida

Umatilla, Florida

Zephyrhills, Florida

Belle Rose, Louisiana

Doyline, Louisiana

Prairieville, Louisiana

Sulphur, Louisiana

Las Vegas, Nevada

Hilton Head Island, South Carolina

Alice, Texas

Austin, Texas

Corpus Christi, Texas

Galveston, Texas

Houston, Texas(3 reports)

Humble, Texas

Mansfield, Texas

Navasota, Texas

San Antonio, Texas

Spring, Texas

Sugar Land, Texas(2 reports)

Universal City, Texas

show all

Gardeners' Notes:


On Nov 14, 2015, georgemykonos from Mykonos,
Greece wrote:

grows very well in Mykonos, Greece.


On Jul 5, 2013, cat_bear from Timberwood Park, TX wrote:

I love this plant because it is something with a beautiful bloom that the voracious deer in my neighborhood won't eat. My plants had a hard time coming back after a very cold San Antonio winter, so I bought more to add to the bed. The containers were large, so I divided each into three plants, which did not bother the iris at all. Now they have been growing beautifully for several years, but have slowed down a little in their blooming. I tried cutting into the plant with a sharp shovel and replanting bits of the plant in other areas of the yard in sun, shade and part shade areas as an experiment. Will report back with my results.


On Feb 27, 2009, txlady from Houston, TX (Zone 10b) wrote:

I had never seen this plant before until I saw it at my office in our beds. I happened upon the landscaper one afternoon and talked him into giving me a piece because he was thinning it out. I planted it and by the next spring it was huge! I divided it into 4 plants and spead them around. This year all over town they are blooming beautifully, but not mine. Does anyone know what to feed them? Bulb food? Flower blooming fertilizer? I have put compost around them every year for 3 years, but not yet this year.


On Apr 23, 2008, passionflower2 from Longview, TX wrote:

I have planted these iris in full sun, they are in very good soil conditions and watered regularly, yet did not come back after the winter weather like the Louisiana swamp iris did. Very sparsely leaved and no blooms. No sign of disease or insects. I probably have twenty 3-gallon plants.


On Jun 12, 2006, loves2dig from Sacramento, CA wrote:

This plant is grown in Zone 9 California,
It is very popular in commercial applications, as well as home landscape.
It grows larger here width/height 3'-4' seems to be pest free,( but dosen't do well with alot of water), it's drought tolorent. I'm planting it now on the eastern facing side of the house in full sun, late afternoon shade, to hide the air conditioning unit. I will be dividing this plant into 4 sections. update to follow
Thanks, Sherry


On May 22, 2006, snuzi from Belle Rose, LA wrote:

This plant does great no matter where its planted in this zone..However it does its best when it gets partial sun and is in cool moist area. Makes a beautiful side dressing near a pond due to the humidity. Easily divided with spade. I have propagated by seed, germinates easier indoors in a mini-greenhouse using moist peat mixture expandable pods.